hey there... is 700W enough for 50size extra 330L for 3D flight?

Well, using the chart for watts per pound, what's the weight of your plane?

50 watts per pound for an easy flyer
75 watts per pound for a sport flyer
100+ watts per pound for a high performance

CGr

I've been told you want at least 150 watts/lbs for 3D, and maybe even closer to 200watts/lbs for stupid vertical.

Yep, I've read that too.. that's where the + comes in.

CGr.

I can give you a couple of examples FYI...

AXi 4120/14 and E-Flite Power 46 outrunners...
They are virtually identical in size, wt. and performance...

I have 13x8E APC props on both...
CC Phoenix ESC's (80A. on the AXi and 60A. on the Pwr 46 )
4 cell Kokam 3200's and both are approx 700 to 750 Watt power units.

The AXi is in a Hangar 9 Pulse XT 40 and the Pwr 46 is in a GP PT 40 trainer.
They weigh between 5.5 and 6 lbs. (PT 40 is heavier )

They will take off in a light breeze in about 30 - 40' and climb straight up for between 100 and 200' depending on how hard I want to push it.



Long story short(ened )
700 Watts will fly that airplane adequitely...but for real 3d "Huckin" I would say not quite...you'd probably want closer to 1K Watts. (or maybe more? )

Good lord... 1KW... heck, we don't have RADARs that put out that much power!!! ha.. oops.. sorry about that.

CGr.

Well...not really knowing how the OP wants to fly it...
Just a WAG...but if he equips it with a battery that's large enough to give decent duration, and deliver strong power...the airplane might weigh perhaps 6 lbs. or more?
150W. / lb. would be approx 900W. soooo.....

I'm still flying the 2 airplanes I listed above with 3200 Kokam 4 cell packs, that I bought in '06...
They still deliver 55A. at WOT when fully charged to 16.8V. (no load...don't remember right off hand what the V. drops to under load, but I recall seeing between 700 and 750W. between the 2 motors ) but if I push things, my flight times are only about 5 or 6 minutes. max.
IIRC they weigh about 14 oz. (I'd have to check to be more accurate )

If I were to buy some new packs, I would choose something like between 4000 and 5000 mah. (and because of newer technology, they would be approx. the same wt. as the old 3200's )

Nope.

A 50 sized Extra will come in around 6-7 lbs or so.

Assuming 7.4lbs All Up Weight, then you would want 1110 watts or so.

Give 1110 watts @ 14.8v that's a 75A draw... so I'd go higher on the voltage to drop the amperage a bit.

745watts = 1 HP so your 700w estimate would result in a quite anemic .50 size plane.

A decent .46 AX is rated to about 1.7HP or a more realistic 1.5HP so 745w x 1.5 = 1117.5w which is in line with the above estimate.

And that's assuming a LIGHT plane... I have a .50 Extra 330S where I use a .75 Super Tigre engine, which I find to be a perfect combo for this plane.


FYI: I run 800-900 watts on my .32 sized Electric planes and about 700-800 watts on my .25 sized electric planes, which gives you a point of comparison.

This too corresponds to the equivalent engines.

FYI I ran across a thread on another forum (since we were down here! ) that pointed me to this : > [link=http://www.effluxrc.com/WM400-mkII-Fan-Motor-Combo-6s-WM400-mkII-6s.htm]Click me![/link]

I was so impressed that I immediately ordered one with the heat sink and nacelle.

It's going into a small .25 sized Bobcat style pusher prop plane, to turn it into an EDF instead...

That's 2000 watts in a .25 plane, using 6S batteries...

thanks guys... I was just checking... knew I needed at least 1000W... just wanted to double check... someone wanted to sell me plane with motor only being capable of 700W...

Zoom zoom... It ought to go pretty good, I'd say!!!